The researchers have suggested the lens-shaped layer of
sediment, which dates from between 381 AD and 612 AD and covers an
area of 50km2, is linked with the tsunami which was caused by a
rock fall in the Rhone delta at the opposite end of the lake.

A model of the event created by geologist Guy Simpson of the
University of Geneva suggests that an eight-metre-high wave would
have struck Geneva 70 minutes after the rock fall.

Simpson says that the findings point to the possibility of
future tsunamis in the area: "It's certainly happened before and I
think we can expect that it will probably happen again
sometime."